The semiconductor device includes one which comprises a wiring board, and a semiconductor chip connected thereto and directing its functional surface to one surface of the wiring board, the functional surface being formed with a functional element.
The wiring board is formed with a conductive film which extends from the one surface thereof connected with the semiconductor chip to the other surface thereof opposite from the one surface thereof via an end face of the wiring board. The conductive film includes: an external connection portion for connecting the semiconductor device to a mounting board, the external connection portion extending from the end face of the wiring board to the other surface thereof; and a wiring portion for interconnection between the semiconductor chip and the external connection portion, the wiring portion being formed on the one surface of the wiring board.
Such a semiconductor device is obtained by connecting individual semiconductor chips to individual wiring boards in a greater board (hereinafter, referred to as “base substrate”) which is formed with the plurality of wiring boards therein and then, cutting the base substrate into the individual wiring boards. In this process, the base substrate is mechanically cut by means of a cutting tool such as a dicing blade.
The base substrate is formed with through holes, each of which spans a boundary between a pair of adjoining wiring boards and extends through the base substrate in a thickness direction thereof. The conductive film formed of a metal material is provided on an inside surface of the through-hole and on its peripheral areas on the one surface and the other surface. The wiring board provided with the conductive film including the external connection portion and the wiring portion is obtained by cutting the conductive film together with the base substrate.
Patent Document 1: Japanese Unexamined Patent Publication No. 2002-50714